The compound adjective 'star-filled' is a transparent modern English formation. Its first element, 'star', descends from the Proto-Germanic 'sternǭ', which itself derives from the Proto-Indo-European root 'h₂stḗr', a term for a star. The second element, '-filled', originates from the Proto-Germanic verb 'fullijaną', meaning "to make full". The compound logically combines these two concepts, following a common English pattern (e.g., smoke-filled, joy-filled) to create a descriptive term that literally means "made full of stars," directly picturing a sky densely populated with celestial bodies.

Structure: star (celestial body) + filled (made full) - star: From Old English 'steorra', of Germanic origin; related to Dutch 'ster' and German 'Stern'. Functions as a noun root denoting a celestial body. - filled: From Old English 'fyllan' (to fill), of Germanic origin. The past participle form '-filled' functions as a combining form meaning "made full of" or "containing a lot of".